In some inkjet printers, a stationary, substrate wide print bar is used to print on paper or other print substrate moved past the print bar. Substrate wide print bars usually include multi-part flow structures with complex pathways through which ink flows from the ink supplies to the printheads on the print bar. Such pathways often necessarily include horizontal sections where it is more difficult to remove air bubbles that can impede the flow of ink.
The same part numbers are used to designate the same or similar parts throughout the figures.